This invention relates to an improved system and method for replacing the background of a digitally captured image record.
Photographic scenes and their images may be divided into distinct parts on the basis of their importance to overall scene content. In every scene there is usually some part that represents the subject of major interest with the remaining pans providing context. Generally, parts in the foreground of a scene usually predominate over background parts, but this is not always so because there are obviously those cases where the background conveys information vital to an overall understanding of a scene's full information content. However, there are kinds of scenes where the background is really of little significance and may even detract from the foreground. Most of these involve scenes populated by one or more nearby humans where the backgound could be dispensed with altogether or otherwise rendered unobtrusive. Official settings demanded for passports, identification badges, and drivers licenses are but a few examples of this type of scene which are contrived to eliminate any influence a background may have on the subject.
To have an "official" photograph made typically requires a specially designed and lighted setting in a studio or photography shop. Here, a neutral featureless background is supplied to provide a uniform field against which the subject's face or upper body is photographed. While this procedure is not generally inconvenient, it is not as convenient as being photographed at a booth or kiosk designed for autophotography, where one can take one's own photograph.
With traditional autophotographic devices, the background and illumination of the studio setting is usually mimicked but without the disadvantage of relying on a professional photographer to take the actual "picture". More recently, autophotographic devices have been advocated which allow a subject to be photographed against some ambient background that can change, thus eliminating the need for providing a real controlled background. Instead, it is proposed that the scene be imaged, the foreground and background separated, and the original background replaced by a preferred one suitable for the official purpose at hand--all to be done via digital image processing techniques. Afterwards the new image may be reproduced in hard copy form.
One example of conventional background replacement is disclosed in U.S. Pat. No. 5,400,081 issued Mar. 21, 1995 to Chaplin, where a chroma key control signal is used for background suppression and new background shaping. Suppression is accomplished by constructing a vector for the imperfect color background scene with a hole in it where the foreground subject is located. The vector is constructed by scaling the vectors for the imperfect color background by the chroma key control signal in mixer circuits for luminance and chrominance components, respectively. The outputs from the mixers are subtracted from the video signal so that only the foreground signal remains.
Although the above and other methods of background replacement are known in the art of electronic digital image processing, none of the known methods discloses or suggests the novelty of the inventive method and system as disclosed and claimed herein. Consequently, the primary object of the present invention is to provide a novel method and system for background replacement of a digitally captured image. This and other objects will become apparent in view of the following descriptions, drawings and claims.